Device for lapping gauges



Feb. 26 1924.

' 1,485,321 G. E. WILKINSON DEVICE FOR LAPPING GAUGES Filed May ,,1

Patented Feb. 26, 1924.

GEORGE ED. WILKINSON, or ELGIN, ILLINOIS, nssIeNonITo ELGIN lST ATITON AL wa'rcn; COMPANY, or CHICAGO, ILLINoIsn ooaronarIoN or ILLINOIS;

" nnv oz-i FOBQ APPING GAUGES.

Application filedMay 26,

To all whom it may concern.

Be it-lrnown that I, GEORGE E. WILKINSON, a citizen of the United States, residing'at Elgin, in the county of Kane, State of Illinois, have invented certain new anduseful Improvements in Devices for Lapping Gauges, of which the following is a description, reference being had to the accompanying drawing and to the figures of reference marked thereon.

This invention relates to a device for grinding the opposite faces of gauges which are required to be very accurate as to thickness, and as to the parallelism, flatness and smoothness of their opposite faces.

' The object of the present invention is to provide a simple, compactly arranged mechanism adapted to be attached to a lathe chuck or other rotating means which will grind the opposite faces of gauge blocks to a required dimension, producing smooth, flat, parallel faces. V i

In the accompanying drawings, which show by way of illustration one embodiment of the invention I v Figure 1 is a sectional view of the device, showing the splined driving connection between the two lapping members and the manner of holding the work; r a

'Fig. 2 is a plan lviewof the'worl: holding means with its connections for producing an oscillating motion thereof; and

Fig. 3 is a view in elevation and plan of one of the gauges.

The device consists of a lapping member adapted to be rotated by a lathe ohuckand provided with a centrally projec'ting'post on which is splined an opposed lapping member. This splined connection includes a spring for constantly forcing the lapping members together as they rotate. Between the fiat opposed faces of these members and spaced therefrom, there is arranged a work holder adapted to hold a number of gauge blocks in position to be ground. The work holder is given an oscillatory motion relative to the grinders either by hand or by appropriate mechanism. 7

Referring more particularly to the drawings, the lathe chuck or other rotatable means 1 is adapted to receive the lapping member 2 provided with thecentral post 3 preferably threaded thereto at its inner end. Adapted to be rotated by the first lapping 1919. Serial No; 2259,7431

member 2 is an opposing. lapping member: lprovided .With a central bore 5 through' which said post 3; passes. Projectingv through the side of this opposing lapping.

member 4 is'a pin 6 the end of which takes in a groove 7- cut in a central boss 8 of the post 3. By means of this splined connection,

nor

the lapping members 2 and 4t arerotated together while permitting a relative move ment toward and from each other. a

To produce thismovement, there is seated in the central bore 5 of the opposing lapping member a and surrounding the post 3 therein a coiled spring 9, one end of which presses against a steel Washer 10 seated in the bottom of the central bore, To provide this seat, the inner wall of the bore 5 projects inwardly, as at 11. The otherend of the spring 9 takes against a spool-like block 12 surrounding the upper portion of said post 3; This spool 12 is provided with upper and lowerffianges 13 and a central annularchannel 14c for the reception of a pin 15 threading through the side'of the opposing lapping member 4 whereby said'spring 9 is housed within said hole and is prevented .from springing out when the device is disassembled. Threaded to the projecting extremity of the 'post 3 is thespring adjusting nut l6which in turn receives aloe-king screw 17 through its open bore. When the end of this screw l'? is threaded into contactwith the end of the'post 3, the nut 16 is locked in position.

' The gauges 18 to be groundv are held be- 1 tween'the two lapping members'2 and aby means of any convenient work holding'device herein shown as a'fiat-plate ringi l9 pro vided with a concentric raceway 2O forthe reception of the gauge blocks 18. The central portion 21 of the ring is provided with a bore through which freely passes the rotary post 3. Arranged on eachside of the fiat sides of thisring 19 are spacing plates 22 and 23, preferably located in recesses 24 and 25 in the opposing facesof the lapping members. By means of this construction the work holding ring is not only held in exact parallelism with the faces of the lapping members, but is suitably spaced there from so as not to be ground thereby.

The work holding ring may be either oscillated by hand or may be moved in relation perience.

In operation, by unscrewing the nuts 16:

which are caused to reciprocate by the cams 30 and 31 revolving independently of each other at such speeds as are found best by exand 17 from the post 3 the opposing lapping memberet is free to be withdrawn from the lapping anember 2 so that the gauge blocks can be inserted in the raceway 20 of the work holder 19. The parts are then reas-' sembled and rotation imparted to the grinding members while, atithe same time, the w rk holder is oscillated by its connection with the cams. As the gauges are reduced in thickness, the pressure of the spring 9 forces the second lapping member l toward the first. At fixed intervals the gauges are removed and transposed to otherlocations in the ring, to insure a uniformity" in grinding. c

Having thus described the invention, what I claim as new and desire to secure by Letters-Patent is:

1. In a device of the class described, the combination of a rotating lapping member, a second lapping member spaced therefrom and positively rotated thereby, work holding means normally arranged between said lapping members means for moving said work holder relatively to said lapping members, and means for moving one of the lap:

ping members toward the other as the gauges in the work holding means are reduced in thickness.

2. In a device of the character described, the combination of a lapping member adapted to be attached to a lathe chuck to be rotated thereby, second lapping member spaced from said first lapping member, and positively driven thereby, work holding means normally permanently located between said lapping members, spacing mem bers between said work holding means and said lapping members to keep the faces of said lapping members in parallelism, and means for moving one of said lapping members toward the other as the w rk is redriced in thickness, 7

3. In a device of the character described, the combination of a lapping member adapted to be attached to a lathe chuck to be rotated thereby, a second lapping 'member spaced from, but directly connected to said first lapping member to be positively driven thereby, work holding means normally concentrically lecated between said lapping members, spacing members between said work holding means and said lapping members to keep the faces of said lapping members inclpara-llelism, means for moving one of said lapping members toward the other as the work is reduced in thickness, and" means for moving said work holder laterally during the lapping operation.

4. In a device of the character described, the combination of spaced lapping members concentrically arranged and posit-ively int er connected, means for rotating'one of said members, concentrically arranged spacing members bet-ween said lapping members and the work holder to keep said lapping faces in parallelism, means for moving one of said lapping members toward the other as the work is reduced in thickness, andmeans for moving the work holder laterally of and, during the rotation'of the lapping membersl 5. In a device of the character described, the combination of a rotating lapping member provided with a centrally arranged post, a centrally. bored lapping member spaced from said first lapping member and splined to said post for rotation thereby, work holding means arranged between said lapping members and adapted to be moved relatively thereto, a spring arranged in said bore surrounding said post and adapted to press said second lapping member toward the first lapping member, and means for adj usting the tension of said spring.

In testimony whereof, I affix my signature in the presence of two witnesses 

